From the ICCF site:
Players who wish to have access to the 7 men tablebases may purchase any of the following programs: ChessOK Aquarium 2017, Houdini Aquarium 2017, Houdini PRO Aquarium 2017, Chess Assistant 17 with Houdini 5 and Chess Assistant 17 PRO with Houdini 5 PRO.
Free Android application
One more way to access 7-man tablebases without having a key is to use Android application.
Search for Lomonosov Tablebases or use https://play.google.com/store/apps/details?id=com.convekta.android.lomonosovtb
Alternatively, if players only want access to 6 men tablebases they may visit this page to use the 6-piece Nalimov tablebases: http://chessok.com/?page_id=361